Significance: Despite early success with antiretroviral therapy (ART) in sub-Saharan Africa, structural and non-structural barriers commonly cause adherence challenges. Inability to overcome these barriers and sustain first line ART has significant implications individual and public health, as well as cost. The proposed study will use SMS texting and existing social support networks to develop a real-time adherence intervention with minimal burden on healthcare systems. Innovation: The proposed study is innovative in 1) its use of real-time adherence monitoring and intervention, 2) targeted intervention based on an individual's adherence behavior, 3) engagement of social support networks for provision of individualized support, and 4) determination of mechanisms of effect of SMS and social support, thus making it possible to design and test evidence-based interventions. Approach: The proposed intervention is based on a conceptual framework in which SMS trigger social support for improved adherence, as well as directly overcome adherence barriers. In a cohort of HIV-infected individuals starting ART and monitored with Wisepill, we will serially test 1) daily SMS reminders, 2) weekly SMS reminders, 3) SMS reminders linked to real-time detection of missed doses, and 4) SMS reminders plus SMS notifications to members of their social support networks- both linked to real-time detection of missed doses. We will conduct qualitative interviews to learn the experiences of participants and members of their social support networks with each type of SMS. This staged approach in a single cohort will allow us to fully understand and compare the additive effects and acceptability of SMS-based interventions. We will also determine behavioral effect mechanisms, as well as compare the impact of each type of SMS with a control population receiving only Wisepill monitoring on adherence and HIV RNA. We propose the following aims: Aim 1. Develop an ART adherence intervention based on SMS reminders linked to real-time detection of missed doses, and assess its acceptability, feasibility and preliminary impact on adherence and HIV RNA suppression. Aim 2. Develop an ART adherence intervention based on social support linked to real-time adherence monitoring and assess its acceptability, feasibility and preliminary impact on adherence and HIV RNA suppression. Investigators: Dr. Haberer (PI) is the emerging academic leader of real-time ART adherence monitoring, particularly in resource-limited settings. Dr. Musiimenta provides key experience in mixed method evaluation of HIV/AIDS-related information systems in rural Uganda. Dr. Ware is a medical anthropologist with extensive experience conducting qualitative interviews on ART adherence behavior in sub-Saharan Africa. Dr. Bangsberg is an internationally recognized leader in adherence to ART and Dr. Haberer's primary mentor.